Police have warned teenagers not to advertise house parties on social networking websites after two celebrations in Norwich were targeted by gatecrashers.

More than 100 people aged between 14 and 17 years old turned up at one party in Sprowston at the weekend after an invitation was placed on Facebook. Officers attended after complaints of noise and the crowds were broken up before there was any trouble.

A second party in Old Catton also had to be broken up by officers after it got out of hand.

Sgt Pete Scott from the Sprowston and Spixworth safer neighbourhood team said parents should keep an eye on social networking sites to avoid such incidents.

He said: 'Parents need to be aware of where their children are, who they are with and what they are doing to avoid situations like this.

'It is also advisable for parents to monitor social network sites and report events which could potentially get out of hand by viewing the number of acceptances.

'Police work in partnership with local housing associations and may take further action against households who disrupt the local community. Tenants risk eviction.'

To report anti-social behaviour contact your social neighbourhood team on 0845 4564567. Always dial 999 in an emergency.

- Are you a parent whose child's party has gone wrong after it was advertised online? Contact Ben Kendall on 01603 or email ben.kendall@archant.co.uk